WHAT IS AN ESOPHAGEAL MOTILITY DISORDER?

The esophagus is a muscular tube that extends from the neck to the abdomen and connects the back of the throat to the stomach. When a person swallows, the coordinated muscular contractions of the esophagus propel the food or fluid from the throat to the stomach. If the muscular contractions become discoordinated or weak, interfering with movement of food down the esophagus, this condition is known as a motility disorder. Motility disorders cause difficulty in swallowing, regurgitation of food, and, in some people, a spasm-type pain.

The esophagus is a muscular tube that extends from the neck to the abdomen and connects the back of the throat to the stomach. (Click on the illustration to enlarge it.)

WHAT IS ACHALASIA?

Achalasia is one of several subtypes of esophageal motility disorders. It is characterized by the absence of muscular contractions in the lower half of the esophagus and by failure of the valve at the bottom of the esophagus to open and let food into the stomach. People with achalasia experience a progressive difficulty in eating solid food and in drinking liquids that can take years to evolve. They often experience regurgitation, and sometimes have spasm-type chest pain. They require much more time than the average person to eat a meal because food traverses the esophagus so slowly. People with achalasia also sometimes lose weight when their condition becomes advanced.

WHAT CAUSES ESOPHAGEAL MOTILITY DISORDERS AND ACHALASIA?

The reasons for why the esophageal muscles fail to contract normally in patients with motility disorders, including achalasia, are unknown. It is likely that the reasons for failure of coordinated muscle contractions depend on the type of motility disorder. In patients with achalasia there are nerve cells within the muscle layers of the esophagus that appear to degenerate for reasons that are not currently understood. Similar problems have not been identified in patients with other types of motility disorders.

HOW COMMON IS ACHALASIA, AND WHO GETS IT?

Achalasia develops in about 3,000 people in the U.S. annually. It usually is diagnosed in adults, but can occur in children as well. There is no particular race or ethnic group that is affected, and the condition does not run in families.

HOW DO I KNOW IF I HAVE ACHALASIA OR AN ESOPHAGEAL MOTILITY DISORDER?

Motility disorders are persistent problems, usually lasting months or years, so if you experience only a brief episode of symptoms it is unlikely that you have a true esophageal motility disorder. The main symptoms of motility disorders are difficulty swallowing, regurgitation of food, and pain. Not all people experience all of these symptoms. People who have achalasia notice difficulty swallowing as the primary symptom, and may ultimately have regurgitation of food as well. Pain is a relatively uncommon symptom of achalasia.

HOW ARE PEOPLE EVALUATED FOR POSSIBLE ACHALASIA AND ESOPHAGEAL MOTILITY DISORDERS?

People who have difficulty swallowing should undergo endoscopy to ensure that no cancer exists as an explanation for this symptom. Endoscopy is performed on an outpatient basis under sedation. The physician passes a small, flexible telescope through the mouth, down the esophagus and into the stomach, providing an opportunity to assess the lining and muscular activity of the esophagus and stomach. Motility problems are sometimes suspected if the physician identifies a muscular narrowing at the level of the valve between the esophagus and stomach, changes in the appearance of the lining of the esophagus, or the finding of retained food in the esophagus.

Many patients who have a suspected esophageal motility disorder undergo an x-ray of the esophagus. This is done while the patient swallows a thick liquid that is visible under x-rays, creating a picture of the lining of the esophagus and stomach. Discoordinated muscular activity within the esophagus can sometimes be seen using this test.

One of the best tests to evaluate for achalasia and other esophageal motility disorders is manometry. This test is performed on an outpatient basis. A small tube is passed down the patient's nose and into the stomach. As it is gradually withdrawn, the patient is instructed to swallow sips of water, permitting the technician who performs the test to measure the strength and coordination of contractions of the esophageal muscles. Some motility disorders, including achalasia, have very characteristic abnormalies of esophageal muscle function that are evident using this test.

WHAT TREATMENTS ARE AVAILABLE FOR ACHALASIA?

Endoscopic Treatment

There are several successful treatments available for achalasia. Unfortunately, there is no useful oral drug therapy available. If left untreated, the symptoms of achalasia will progress over time.

Two types of treatment are performed under sedation using endoscopic guidance. One, known as pneumatic dilation, involves placing a balloon in the swallowing passage at the level of the valve between the esophagus and stomach. This balloon is forcefully expanded, tearing the muscles of the valve so that the valve no longer obstructs passage of food from the esophagus into the stomach. This has a 75% chance of relieving symptoms for a period of years, but has a 3% risk of rupturing the esophagus. If esophageal rupture occurs, then emergency surgery is necessary to repair the rupture and then treat the achalasia surgically.

The other type of treatment that is performed under endoscopic guidance is botulinum toxin, or Botox, injection. This toxin paralyzes the muscles of the valve between the esophagus and stomach, permitting food to pass from the esophagus into the stomach. Over 60% of people who have this therapy get substantial relief of symptoms for at least one year.

Surgical Treatment

Surgery is recommended for many patients with achalasia. The operation is designed to cut the muscles of the valve between the esophagus and stomach, permitting food to pass from the esophagus into the stomach. The operation has been performed since early in the 20th century with good results. For much of this time it was done through an open incision in the abdomen or through an incision in the left side of the chest between the ribs. These types of incisions often required hospitalization of up to a week for adequate recovery. Since the early 1990s the operation has been done using telescopic techniques that permit patients to go home much earlier, often the day after surgery. Almost 95% of patients who have surgery for achalasia experience relief of symptoms for many years after the operation.

It should be understood that, since physicians don't know the underlying cause for achalasia, it's not possible to restore the function of the esophagus completely. Most patients will have some residual symptoms after successful therapy but should be able to carry on a nearly normal lifestyle.

HOW ARE OTHER ESOPHAGEAL MOTILITY DISORDERS TREATED?

Most esophageal motility disorders don't require specific therapy. When symptoms are particularly bothersome, some patients are treated with drugs that relax the muscles of the esophagus, helping to decrease the discoordinated activity. Rarely, surgery is necessary to cut the muscles that are causing symptoms. In some patients the discoordinated activity is thought to be due to irritation of the lining of the esophagus by stomach acid, and treatment of acid reflux is appropriate.